Two return exits or one?

[iguana-pr]

Currently I am working on a closed loop for my tank. The tank is not drilled so I will use PVC pipe over the rim. I will use a MAG7 and according to the Head Loss calculator, I should be getting about 550gph using 1" pipe.

My question is regarding the return pipe. Which is better, two returns via a T with about 225gph on each or a single return with 550gph?

Also, what if I use a PVC bushing to reduce the output to 1/2" and use a spreader nozzle. How will this affect the flow?

Thanks

[FunkieReefJunkie]

Ok let me see if I understand you correctly. Your tank is not drilled at all for returns. If this is so you'll have to rely on those annoyingly problematic u tube siphon things. I say annoying because if and when they lose siphon your going to have flooding.

Two return pipes are better than one because if some big arse snail or some algae gets in one you'll have the other to keep flowing. And I would not connect two returns tead off into one. Same issue as above.

Something to keep in mind and I learned the hard way: Two smaller pvc pipes instead of one or two larger pipe for returns will restrict the flow of your returns. Better to go with the larger.

Is your tank acrylic or glass? Acrylic is easy to drill. As simple as purchasing a hole saw for your drill.

[iguana-pr]

Thanks for the reply.

The tank is already setup but I have 6 MJ1200 powerheads which I would like to get rid of. I have two Amiracle overflow boxes to the sump/refugium.

I have a MAG7 doing nothing which I think will work great as a CL pump. I will do sort of an inverted U over the rim using 1" PVC down to the cabinet where the MAG7 will be. For the return, I am not sure if it will be better to T the return line into two outlets for half the flow each, or just one outlet with the entire pump throughput. So good flow from just one outlet or halfway decent flow from 2?

[FunkieReefJunkie]

Two at full flow, for reasons as stated above. ;)

[iguana-pr]

OK Thanks